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Sulfate attack and its effects are important from both scientific and industrial viewpoints. It is perceived that cements containing pozzolan have better performance in sulfate solutions, since the pozzolanic reactions reduce the quantity of calcium hydroxide and increase calcium silicate hydrate. This paper investigates the physical and mechanical properties of concretes made by blended cement containing Algerian natural pozzolan of volcanic origin, and Portland cement. In order to better determine the pozzolanic effect of the pozzolan addition in the concrete, the analysis of the experimental results of the effect of the partial replacement of the cement by the natural pozzolan showed that it contributes positively to the improvement of its mechanical characteristics, its durability with respect to the permeability to the chlorine ions, the ultrasonic pulse velocity, the compressive strength as well as the sulphate resistance. The present study confirms the pozzolanic reactivity of the natural pozzolan used

In Algeria, locally available natural pozzolan of volcanic origin material has the potential for use in environmental friendly concrete as a partial cement replacement. This paper studies the effect of replacement level of pozzolan concrete in sulphated environment. The natural pozzolan has a marked influence on the properties of the concrete. When it is coupled to a water reducing superplasticizer by a correct adjustment of the composition, it greatly improves the concrete properties. The analysis of experimental results on pozzolan concrete at 5% content and fineness of 9565 cm2/g exposed in sulphated environment, show that it positively contributes to the improvement of its mechanical, physical and physico-chemical characteristics. Trough this research work, parameters such as compressive strength development, chloride permeability, water absorption and sulphates resistance are studied.

The natural pozzolan of volcanic origin has a marked influence on the physico -mechanical characteristics of the concretes. When it is coupled to a water reducing superplasticizer by a correct adjustment of the composition, it greatly improves the concrete properties. The analysis of the experimental results on pozzolana concrete at 5% content and fineness of 9600 cm 2 /g, in a sulphated environment, showed that it contributes positively to the improvement of its durability with respect to the Chloride permeability. This test was performed using the procedures of ASTM C 1202. The resistance of concrete to penetrating chloride ions was measured by the charge passed through two 50 mm disk concrete specimens maintained under an electric tension of 60V during 6 hours by means of electrodes made of rustproof steel between the two cells of the two compartments. One of the faces of the specimen was in contact with 3% NaCl solution, and the other face was in contact with 0,3N NaOH solution. The test was conducted at 28, 90,180 and 365 days

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